Risk–benefit evaluation of on-line high-performance liquid chromatography analysis for pooling decisions in large-scale chromatography

In the production of a human therapeutic protein from inclusion bodies, product related impurities of very similar size and charge to the product are created as byproducts of the refold process. Their removal is usually challenging even when using chromatography with high performance resins and elution by shallow linear gradients. Additionally, performing this type of separation for commercial production adds increased complexity. To maximize productivity, columns are loaded so high that product elution profiles are not well separated from the impurities and pooling decisions are challenging. In this paper, conventional UV pooling based on fractionation or predefined absorbance based criteria will be compared to pooling based on fast on-line HPLC analytic. The development and implementation in a GMP process will be shown for a specific challenging separation by hydrophobic interaction chromatography. The different approaches have their unique complexities, timelines, uncertainties, and risks during development and implementation as well as during manufacturing. This study presents a probabilistic framework for quantitative comparison of two processes with unequal variability and uncertainty to evaluate the potential benefits of a PAT technology for its routine use in GMP Bioprocess manufacturing.